Shift Work Disorder (SWD) is a circadian rhythm sleep disorder that affects individuals whose work schedule conflict with the body’s natural sleep-wake cycle. People who work night shifts, rotating shifts, or early morning shifts are at risk of developing SWD due to the misalignment between their internal biological clock and their work demands. Common symptoms include excessive sleepiness during work hours, difficulty falling or staying asleep during rest periods, reduced alertness, and fatigue. Over time, untreated SWD can lead to poor job performance, irritability, depression, and increased risk of chronic health conditions like cardiovascular disease and diabetes. 

Shift work sleep disorder is characterized by excessive sleepiness when you wish to be awake (often during the night shift) and difficultly sleeping when you wish to be in bed. The insomnia may occur:

• when trying to sleep during the day after a night shift
• when trying to shift back to a regular schedule of sleeping at night

The constant rotation of schedules prevents the brain’s internal clock from synchronizing with the external environment leading to excessive sleepiness or insomnia. Problems can also be exacerbated when attempting to shift back to a normal schedule on days off from work so as to be on the same schedule as the rest of the family.

Shift workers are more likely than day workers to experience:

•  stomach problems
• menstrual irregularities
• illness
• weight gain
• heart problems 
• high blood pressure
• higher risk for diabetes

Diagnosis of SWD is based on a thorough clinical evaluation, including a review of work and sleep schedules, symptoms, and a sleep diary. In some cases, actigraphy (a wrist-worn device that tracks sleep patterns) or a sleep study may be recommended to rule out other sleep disorders.